Valve devices known from the prior art generally have a housing body with a fluidic chamber, with two or more flow ducts opening into the fluidic chamber, and with a valve seat associated with at least one of the flow ducts. Further provided is a valve body which can be moved by a valve drive between a closed position, in which it covers the valve seat, and an open position, in which it exposes the valve seat. Where the valve device involves separation of media, the valve drive is sealed from the fluidic chamber by a flexible diaphragm. This means that a valve device of this type is composed of several parts, which is problematic in particular in the design of a miniaturized valve since the tolerances caused by the manufacture of the individual components and the assembly thereof are very hard to control in cases where very small structures are involved. More particularly, such tolerances may add up in an undesirable manner.